Work rolls and cooling method thereof

ABSTRACT

A method of cooling work rolls in a rolling mill is comprised of forming an axially extending passageway through the work roll and disposing a cooling medium within the passageway for limiting the temperature differences along the surface of the work roll. The cooling medium can be a solid member having a higher rate of thermal conductivity than the material of the work roll or a fluid. The flow path of the fluid cooling medium can be arranged for selectively contacting only certain portions of the roll member within the axially extending passageway.

United States Patent Takao Kawanaml No. 13, Azakltanoyama, Oaqanawa,Uenocho, Chlta-gun;

Toyokazu Salto, No. 39, l-chome, Saltushlta-cho Minaml-ku, Nagoya-shl;l-llro Morl, No. 7, Aza-hlgashiyamada, Oazatukljims, Uenocho, all ofAichi-ken,

[ 72] Inventors Japan [21] Appl. No. 717,611 [22] Filed Apr. 1, 1968[45] Putente'! Sept. 14, 1971 [32] Priority Feb. 5, 1960. Apr. 3, 1967,Apr. 3, 1967 I 3.1 Japan [31 l 43/7418, 42/2766) and 42/21 101 [54] WORKROLLS AND COOLING METHOD THEREOF 5 Claims, 7 Drawing Figs.

[52] US. Cl 72/201 [51] Int. Cl l321b 27/06, B21b 27/08 [50] FieldofSearch 29/110,

[56] References Cited UNITED STATES PATENTS 1,536,832 5/1925 l Ivan s...H 165/89 Primary Examiner-Charles W. Lanham Assistant Examiner-E. M.Combs AttarneyMcGlew and Toren ABSTRACT: A method of cooling work rollsin a rolling mill is comprised of forming an axially extendingpassageway through the work roll and disposing a cooling medium within 1the passageway for limiting the temperature differences along thesurface of the workroll. The cooling medium can be a solid member havinga higher rate of thermal conductivity than the material of the work rollor a fluid. The flow path of the fluid cooling medium can be arrangedfor selectively contacting only certain portions of the roll memberwithin the axi- PATENTEDSEPMIS?! v3.604237 I saw u or 4 INVENTORS fi/maKANANAM/ Tg yoxnzu 474/10 Min/Mom WORK ROLLS AND COOLING METHOD THEREOFSUMMARY OF THE INVENTION The present invention relates to work rolls andcooling method thereof.

When flat products such as steel .strip oraluminum strip are rolled,work rolls of .a rolling mill are generally given a profile so-calledcrown" in order to obtain flatness of finished products. However, incase of continuous rolling, temperature differences take place in workrolls along the direction of roll axis so that the rolls are undesirablydeformed due to heat.

In other words, the thermal deformation is caused by heat due tofriction at bearings of'the work roll, due to plastic deformation work,and heattransmitted from the work piece.

For example, according to the temperature variation of roll observedfrom actual measurements on the temper rolling mill, the differencebetween temperature (A) at the middle portion ofthe work roll barrel andtemperature (B) at the end portions of the work roll barrel revealsitself to be about C., after continuous rolling of 13 coils of materialas shown in the diagram. In general when the temperature difference isover'about 10 C., flatness of rolled products becomes worse, appearanceof the finished products becoming unsatisfactory.

The reason is that the reduction percentage by the temper rolling iscomparatively low and the temperature at .the end portions of the workroll barrel becomes higher .as compared with the temperature at themiddle portion due to heat from work roll bearings by friction.Depending upon the kind of rolling mill, forlexample a .cold reductionmill, the temperature at the middle portion becomeshigher than .at theend portions in which case flatness of rolled products is alsoundesirably injured.

The present invention is intended to overcome the abovementioneddifficulties, andrelates to a'method for cooling .the work rolls andadjusting the temperature thereof which is characterized in thatcoolingmedium is passedthrough a cooling pipe or pipes inserted spacedlyin the central lengthwise hole of the work roll, a method of cooling thework rollsand of adjusting the temperature thereof which ischaracterized in that cooling medium is passed through a cooling pipeorpipes spacedly inserted in the central lengthwise hole of the work roll,said pipe or pipes having openings or slits and .the like thereon inpositions corresponding to a section or sections of the roll to becooled to partially cool the roll or to cool one section or sections ofthe work roll more than the remaining sections and a method of adjustingthe temperature .of the work roll which is characterized in that aheat-conducting medium is inserted in the central lengthwise hole of thework roll to contact partially or wholly with the wall of'said centralhole and further relates toa work roll, characterized in that in orderto prevent thermal deformation of the roll, the difference betweentemperatures at various portions of the roll is kept below about 10C.,and a central lengthwise hole is provided through thecentral portionofthe roll, and in the hole, inlet and outlet .pipes for example, forpassing cooling medium are provided by means of rotary joints, andfurther relates to a work roll, characterized in that in order toprevent thermal deformation of the roll, the difference betweentemperatures at various portions-of the roll is kept below about 10 C.,and at the central portion of the roll, a central lengthwise hole isprovided, in which hole, there is inserted a heat-conducting medium inpartial or whole contact with the wall of the hole.

Additionally, the present invention relates to a joint device forconnecting the rotary joint with the end of the to neck, which comprises.a flange fixed on the end of the roll neck, a cylindrical member, saidflange having partially screwed inside wall and said cylindrical memberhaving partially screwed outside surface, whereby said cylindricalmember is easily mounted or dismounted only by turning the cylindricalmember.

For example, along the axial direction of the roll there is provided acentral lengthwise hole, in which hole a supply pipe of cooling mediumextending from one end of the roll to the other is providedywhich pipeis'supplied with cooling medium in such a manner that the cooling'mediumcoming out at the end of the supply pipe cools the roll, while flowingthrough the space between the supply pipe and the roll, to be dischargedat the rotary joint equipped with .a discharge pipe. in principle :thecooling medium can be flowed in reverse: through the space then throughthe pipe. In this case, it may be also so provided that, as mentionedabove, the roll is cooled by cooling medium flowing from the end of thesupply pipe through the space between the supply pipe and the roll, orso provided that, for example, a number of holes are provided on thesupplypipe in such a manner that the cooling fluid is jetted out throughthe holes.

Thus, when the temperature in a section or sections of the roll becomeshigher than that of other sections of the I'OllyIhIS high-temperaturesection or sections can be separately cooled so .that the temperaturedifference in the roll is kept below about 10 C.

For example, a supply pipe or pipes coaxially or in parallel are placedin the central lengthwise hole in such a position that the coolingmediumcomes out from the pipe to the space between the pipe and the roll atthe position corresponding to the "higher temperature section orsections of the roll, and then the cooling medium is led in'thedischarge pipe after cooling, gathered altogether at the rotary jointpart, and discharged from-the discharge pipeprovided on therotary joint.

Further, for'example, a supply pipe for coolingfluid is providedextending from one end of the roll to the other end in such manner:that, .as mentioned'above, holes are provided so as to be able tosupply the cooling medium to the positions of higher temperature. Thesize of each of these holes are so determined that the supply quantityof cooling medium is controlled according to the temperature differencein order to keep the temperature difference in the roll not higher thanabout i 0 C.

The cooling medium after cooling may be either thrown away or circulatedby providing a separate cooling equipment.

As the cooling medium, for example, water, air or the like may beutilized.

As the sealing between the rotary joint and the roll, an adequatesealing mechanism such as hearing or the like is utilized.v

Apart from the utilization of the above-mentioned cooling medium, incase, for example, the difference between temperatures at the middleportion of'the roll and at the end portions of the roll is above about10 C., along the axialdirection of the roll there-is provided a centrallengthwise hole, in which hole a heat-conducting medium is inserted. Theheat conducting medium inserted is so designed as to be broughtin wholecontact with the inside wall of the roll, or partial contact with it atthe positions having temperature difference to equalize the temperaturethrough the roll barrel. For example, the heat-conducting medium is sodesigned that it contacts with the inside wall of the central lengthwisehole at the positions corresponding to the end .portionsof the work rollbarrel having higher temperature and to the middle portion having lowertemperature in order to give thermal connection between these portions,and the remaining positions of the heat-conducting medium has a smallerdiameter so that these portions do not contact with the roll.

Thus, the heat at the end portions of the roll barrel are thermallyconnected through the heat-conducting medium to the middle portionhaving lower temperature of the roll, so that the temperature differencebecomes remarkably small with the result that the thermal deformationdue to the temperature difference may be prevented effectively.

As mentioned above, the heat-conducting medium is provided in such amanner that it comes in contact with higher temperature portions and thelower temperature portions of the roll and does not'contact the otherpart of the roll; namely the roll and the heat-conducting medium contactwith each other-at certain portions and does not contact at theremaining portions and it is quite effective to fill up the spacesformed around the noncontacted portions, where the roll and the heatconductor are not in contact with each other, i.e. the spaces betweenthe roll and the heat-conducting medium with heat insulation materialsuch as rock wool or the like in order to prevent another temperaturedifference, by preventing the conduction of heat from the portion havinghigher temperature to the portion having intermediate temperaturebetween said higher and lower temperatures.

As the heat-conducting medium, a material such as copper, aluminum orthe like, which has higher heat conductivity than the material of theroll can be utilized.

The advantages, which may be obtained by utilizing the roll according tothe present invention, are as follows.

The thermal deformation due to the temperature difference in the workroll may be almost avoided, so that the yield of rolled products may beremarkably increased.

Further, the frequency of roll exchange is decreased so that the delaytime of the rolling mill can be remarkably reduced as well as theproductivity can be greatly improved.

Further advantages of the present invention are seen in the facts that,the work for exchanging the rolls is decreased due to the diminution ofthe roll exchange frequency, as well as it becomes unnecessary toprepare so many rolls for exchanges as usual, and the work for rollrepair may be greatly eliminated.

and so on.

The present invention will be explained in detail referring to theattached drawings. I

FIG. 1 is an explanatory diagram of the temperature variation in thework roll of a temper rolling mill.

FIG. 2 is an explanatory drawing of an embodiment of the presentinvention in which cooling medium passage is provided by a pipe spacedlyextending in the central lengthwise hole of the roll.

FIG. 3 is an explanatory drawing of another embodiment of the presentinvention in which cooling medium passage is provided by a pipe havingholes and extending in the central lengthwise hole of the roll.

FIG. 4 is an explanatory drawing of another embodiment of the presentinvention in which cooling medium passage is provided by inlet andoutlet pipes extending in the central lengthwise hole of the roll.

FIG. 5 is an explanatory drawing of another modified embodiment of thepresent invention in which a heat-conducting medium is inserted in thecentral lengthwise hole of the roll.

FIG. 6 is a sectional view of the joint device for connecting the rotaryjoint with the end of the roll neck according to the present invention.

FIG. 7 is a cross-sectional view along the line A-A of FIG.

EXAMPLE 1 In FIG. 2 a central lengthwise hole 22, is provided in thework roll 21 of a temper rolling mill, and a water supply pipe 23 isplaced in the central hole 22 by means of rotary joint 24. Sealing ofthe rotary joint 24 and the end portions of the work roll 21 is done bya bearing seal 26 using a sleeve 27. A discharge pipe 28 is provided inthe rotary joint 24.

Cooling water is supplied by the water supply pipe 23 and jetted fromthe end of the supply pipe 23 to cool the one higher temperature endportion 25' of the roll and passes through the space between the watersupply pipe 23 and the work roll 21 to cool the other end portion 25 ofthe roll. The water passes to the rotary joint 24 and is discharged fromthe discharge pipe 28. I, I 7

Almost no temperature difference; between the higher temperature endportions 25, 25 and the lower temperature, and no deformation of therollcrown due to the thermal deformation was observed middle portionof theroll in the after a continuous rolling of 10 coils with the work rollscooled in this way.

EXAMPLE 2 In FIG. 3 a central lengthwise hole 22 is provided in the workroll 21 of a temper rollingrnill, and a water supply pipe 23 havingholes 29 at the positions corresponding to the higher temperature endportions 25, 25' of the roll 21 is placed in the central hole 22 bymeans of a rotary joint' 24.

Sealing of the rotary joint 24 and the end portions of the roll 21 isdone by a bearing seal 26 using a sleeve 27. A discharge pipe 28 isprovided in the rotary joint 24.

Cooling water is supplied by the supply pipe 23Iand jetted from theholes 29 provided in the pipe at the positions corresponding to the endportions of the roll to cool these higher temperature portions, andpasses through the space between the pipe 23 and the wall of the centralhole of the roll to the rotary joint 24 and is discharged from thedischarge pipe 28.

Almost no temperature difference between the higher temperature endportions 25, 25' and the lower temperature middle portion of the rollwas observed and no deformation of the roll crown due to the thermaldeformation was observed after a continuous rolling of 12 coils with thework rolls cooled in this way.

EXAMPLE 3 In FIG. 4, a central lengthwise hole 2 is provided, in thework roll 1 of a temper rolling mill while a water supply pipe 3 isprovided thereon, extending near an end portion 5 of the roll by meansof a rotary joint 4.

The water supply pipe 3 is equipped with holes 6 at the positionscorresponding to the end portion 5, while a discharge pipe 7 isinstalled inside of the water supply pipe 3. The discharge pipe 7 isprovided with holes 8 at the position corresponding to the middleportion of the roll so that the water coming out from the pipe contactswith the roll.

At the lower end of the rotary joint, a discharge pipe 9 is provided. Abearing 1 1 equipped with sealing means serves for the sealing the jointusing a sleeve 10.

Cooling water reaches the neck portion 5 of the roll through i the holes6 of the water supply pipe 3, and cools the end portions 5. Then thecooling water is cut off by walls 12a dividing cooling sections and ledout at the discharge pipe a through the rotary joint.

On the other hand cooling water further flows through the water supplypipe 3, and is discharged at the end thereof and there, cools the otherend portion 5 of the roll. Then the cooling water is cut off by walls12b led into the discharge pipe 7, and is brought in contactwith theroll 1 through the holes 8 of the discharge pipe 7 at the positioncorresponding to the lower temperature middle portion of the roll. Inthis way, since the cooling water, which has cooled the end portion 5'absorbing heat therefrom, comes in contact with the lower temperaturemiddle portion of the roll, the difference between the temperatures atthe end portions 5, 5 and the temperature at the middle portion of theroll becomes extremely small.

Then, the cooling water which has been brought in contact with the lowertemperature middle portion of the roll is led out from the dischargepipe 9 through the holes 8, the discharge pipe 7 and the rotary joint 4.

The wall 12c is installed in order to prevent the cooling water fromflowing into sections where the temperature difference in almost out ofquestion. The roll 1 rotates together with the sleeve 10.

The walls 12a 12b, 12c are fixed on the water supply pipe 3, and anelastic material such as rubber not shown is provided at contact pointsof the walls 12a, 12b, 12c with the roll 1.

Thirteen coils of material were rolled with above-mentioned rolls withthe total rolling time of 75 minutes, and it was found that there wasalmost no difference between the temperatures at theend portions 5, 5'and the temperature at the middle portion of the roll, and any thermaldeformation was not observed.

EXAMPLE 4 1 ln FIG. 5, at the central portion of the roll 5 of a temperrolling mill, a central lengthwise hole 2 is provided extending from oneend of the roll to the other end, and a heat-conducting medium made ofcopper is inserted in the hole 2 in such a manner that the heatconducting medium comes in contact with the higher temperature endportions 5, 5' of the roll 1 and the lower temperature middle portion ofthe roll 1, but does not contact the other portions of the roll, formingspaces 14 there between, as shown in the drawing.

Fifteen coils of material were rolled using the above mentioned rolls 1with the rolling time of 84 minutes, and it was found that thedifference between the temperatures at the end portions and thetemperature at the middle portion was only a little, say 3 C. and anydeformation of crown due to the thermal deformation was not observed.

Now the novel jointing device for connecting the rotary joint with theend of the work roll shall be described referring to FIG. 6 and H6. 7.

A flange 62 is attached on the end portion 61 of the roll R by means ofbolts 64 with packing 63 therebetween. On the inside wall of the flange,screw threads 66 are formed at three portions equally spaced from eachother, into which a rotary cylindrical member 65 is screwed and set bymeans of screw threads formed at three portions equally spaced from eachother on the outside of the cylindrical member. The screw threads on theinside wall of the flange 62 and on the cylindrical member 65 aredesigned in such a manner that the cylindrical member 65 is screwed inthe flange by turning the cylindrical member in the rotating directionof the roll so as to prevent the cylindrical member from being screwedout from the flange by the rotation of the roll.

For setting the cylindrical member in the flange, the screw threadportions of the cylindrical member are mated with the grooves 68 on theinside wall of the flange and the cylindrical member is inserted in theflange operating the handle 67 attached to the cylindrical member 65.And the cylindrical member is turned to set the screw threads of thecylindrical member with the screw threads 66 of the flange 62 by turningthe handle 67.

For disengagement, the cylindrical member is turned 60 in reversedirection to mate the screw threads of the cylindrical member 65 withthe grooves 68 of the flange 62 and then the cylindrical member is drawnout from the flange.

In the drawings, 69 is a small flange having an O-ring packing 610 andattached to the cylindrical member 65.

This flange is engaged water tight with the flange to prevent theleakage of cooling water.

The cooling water from the rotary joint flows through the water supplypipe 611 into the end portion and the inner portions of the roll andpasses through the space 612 between the cylindrical member and thewater supply pipe and is discharged outside the roll through the rotaryjoint.

By the above design, the rotary joint is easily and promptly mounted ordismounted, and a very firm connection can be assured without threat ofleakage of the cooling medium, and the supplyof cooling medium into thework roll can be effectively done, thus saving much of the labor andtime required by the connecting work, and increasing the productivity ofthe rolling mill.

We claim:

I. A work roll for use in a temper rolling mill for rolling steel sheetmaterial and the like comprising an axially extending cylindricallyshaped member having a pair of axially spaced circumferentiallyextending end parts arranged to be positioned in frictional engagementwithin work roll bearings and a circumferentially extending intermediatepart disposed between said end parts and arranged to contact the steelsheet material passing over the work roll, said member having a boreextending in the axial direction therethrough from one said end part tothe other said end part, the bore in said member being closed at one endwithin the other said end part and extending for substantially theentire axial length of said member from one said end part to the othersaid end part, conduit means for conveying a cooling fluid through saidbore and out of contact relationship with the surface of said bore andfor discharging the cooling fluid into said bore into direct contactwith the material forming said member which contacts the steel sheetmaterial for maintaining the temperature of the surface portions of saidmember within a range of about 10 C., said conduit means comprising afirst conduit extending through and centrally positioned within saidbore in spaced relationship with the surface of said bore for forming anannular space therebetween for supplying a cooling fluid from said firstconduit into the annular space for passage over the surfaces of saidmember within said bore so that the cooling fluid is in direct contactwith the material of said member which contacts the steel sheet materialpassing over the work roll, and a second conduit coaxially arrangedwithin and spaced inwardly from said first conduit forming an annularspace therebetween, said second conduit having a first end and a secondend, the first end of said second conduit located within the bore spacedoutwardly from the end of said first conduit adjacent to closed end ofthe bore, and the second end of the said second conduit disposedoutwardly from said bore whereby cooling medium flows into the borethrough said first conduit and after its passage therethrough to theclosed end of the bore is admitted into said second conduit for passagetherethrough and eventual discharge from said member.

2. A work roll, as set forth in claim 1, :wherein transversely arrangedpipe sections are secured to and are in communication with the interiorsurface of said second conduit at one end and extend through the annularspace between said second conduit and said first conduit and are securedat the other end into said first conduit for circulating cooling fluidbetween said second conduit and the annular space located between saidfirst conduit and the surface of said bore.

3. A work roll as set forth in claim 2, wherein a plurality oftransversely arranged annular-shaped plates are disposed between theouter surface of said first conduit and the surface of said bore atspaced positions therealong for forming a plurality of separatedcircumferentially extending compartments in the annular space.

4. A work roll for use in a temper rolling mill for rolling steel sheetmaterial and the like comprising a longitudinally extendingcylindrically shaped member having an axially elongatedcircumferentially extending intermediate portion arranged to contact thesteel sheet material and a pair of circumferentially extending endportions on opposite sides of said intermediate portion and arranged tobe positioned in frictional engagement with work roll bearings, saidmember having a bore extending axially therethrough and closed at onesaid end portion of said member, a conduit for supplying cooling fluidinto said bore and disposed centrally therein and extending therethroughin spaced relationship with the surface of the bore for forming anannular space therebetween, said conduit having one end locatedexteriorally of the bore and the other end located adjacent to andspaced from the closed end of the bore, a joint member secured to saidmember at the open end of the bore therethrough, said joint membercomprising an annular shaped flange disposed about the open end of saidbore and secured to one of said end portions of said member, a

" cylindrical member arranged to be selectively disposed in threadedengagement with the inner surface of the opening in said flange, saidcylindrical ,member spaced outwardly from said conduit and forming anannular space therewith for receiving the cooling fluid flowingoutwardly from the annular space in the bore about said conduit, andmeans for forming a seal between said flange and said cylindrical memberto prevent leakage therebetween of the cooling medium flowing within theannular space in said bore.

5. A wall member, as set forth in claim 4, wherein said flange havingspaced circumferentially extending threaded sections on the innersurface within its opening, said cylindrical member having similarlyarranged spaced threaded sections on its exterior surface for engagementwith the threaded sections on said flange, so that by positioning saidthreaded sections on said cylindrical member between the threaded sec-

1. A work roll for use in a temper rolling mill for rolling steel sheetmaterial and the like comprising an axially extending cylindricallyshaped member having a pair of axially spaced circumferentiallyextending end parts arranged to be positioned in frictional engagementwithin work roll bearings and a circumferentially extending intermediatepart disposed between said end parts and arranged to contact the steelsheet material passing over the work roll, said member having a boreextending in the axial direction therethrough from one said end part tothe other said end part, the bore in said member being closed at one endwithin the other said end part and extending for substantially theentire axial length of said member from one said end part to the othersaid end part, conduit means for conveying a cooling fluid through saidbore and out of contact relationship with the surface of said bore andfor discharging the cooling fluid into said bore into direct contactwith the material forming said member which contacts the steel sheetmaterial for maintaining the temperature of the surface portions of saidmember within a range of about 10* C., said conduit means comprising afirst conduit extending through and centrally positioned within saidbore in spaced relationship with the surface of said bore for forming anannular space therebetween for supplying a cooling fluid from said firstconduit into the annular space for passage over the surfaces of saidmember within said bore so that the cooling fluid is in direct contactwith the material of said member which contacts the steel sheet materialpassing over the work roll, and a second conduit coaxially arrangedwithin and spaced inwardly from said first conduit forming an annularspace therebetween, said second conduit having a first end and a secondend, the first end of said second conduit located within the bore spacedoutwardly from the end of said first conduit adjacent to closed end ofthe bore, and the second end of the said second conduit disposedoutwardly from said bore whereby cooling medium flows into the borethrough said first conduit and after its passage therethrough to theclosed end of the bore is admitted into said second conduit for passagetherethrough and eventual discharge from said member.
 2. A work roll, asset forth in claim 1, wherein transversely arranged pipe sections aresecured to and are in communication with the interior surface of saidsecond conduit at one end and extend through the annular space betweensaid second conduit and said first conduit and are secured at the otherend into said first conduit for circulating cooling fluid between saidsecond conduit and the annular space located between Said first conduitand the surface of said bore.
 3. A work roll as set forth in claim 2,wherein a plurality of transversely arranged annular-shaped plates aredisposed between the outer surface of said first conduit and the surfaceof said bore at spaced positions therealong for forming a plurality ofseparated circumferentially extending compartments in the annular space.4. A work roll for use in a temper rolling mill for rolling steel sheetmaterial and the like comprising a longitudinally extendingcylindrically shaped member having an axially elongatedcircumferentially extending intermediate portion arranged to contact thesteel sheet material and a pair of circumferentially extending endportions on opposite sides of said intermediate portion and arranged tobe positioned in frictional engagement with work roll bearings, saidmember having a bore extending axially therethrough and closed at onesaid end portion of said member, a conduit for supplying cooling fluidinto said bore and disposed centrally therein and extending therethroughin spaced relationship with the surface of the bore for forming anannular space therebetween, said conduit having one end locatedexteriorally of the bore and the other end located adjacent to andspaced from the closed end of the bore, a joint member secured to saidmember at the open end of the bore therethrough, said joint membercomprising an annular shaped flange disposed about the open end of saidbore and secured to one of said end portions of said member, acylindrical member arranged to be selectively disposed in threadedengagement with the inner surface of the opening in said flange, saidcylindrical member spaced outwardly from said conduit and forming anannular space therewith for receiving the cooling fluid flowingoutwardly from the annular space in the bore about said conduit, andmeans for forming a seal between said flange and said cylindrical memberto prevent leakage therebetween of the cooling medium flowing within theannular space in said bore.
 5. A wall member, as set forth in claim 4,wherein said flange having spaced circumferentially extending threadedsections on the inner surface within its opening, said cylindricalmember having similarly arranged spaced threaded sections on itsexterior surface for engagement with the threaded sections on saidflange, so that by positioning said threaded sections on saidcylindrical member between the threaded sections on said flange saidcylindrical member can be disposed in threaded engagement with saidflange by rotating its threaded sections into engagement with thethreaded sections of said flange thereby securing said cylindricalmember in place.